One of the most important steps in solving dynamics problems in physics is understanding the concepts of forces and inertia.
- Forces are any influence that will change the motion of an object. These influences result in the interaction of the object with another object or its surroundings.
- $F = ma$
- $F$ = force
- $m$ = mass
- $a$ = acceleration
- This is Newton’s (Second) Law
- examples: frictional force, gravitational force, tension force, electrical force, normal force, spring force, any applied force, etc.
- Understanding the different types of forces, how they interact, and when they are present will help in creating your Free Body Diagrams when solving your dynamics problem
- $F = ma$
What is Force (~5 minutes):
- Inertia is an object’s tendency to resist a change in its motion (speed, direction, etc.)
- This is Newton’s (First) Law
- example: think of inertia as trying to push a bowling ball vs. a ping pong ball with your pinky finger, suddenly hitting the breaks in a car, being on an amusement park ride and hitting a really sharp turn
Seven Examples of Inertia (~3 minutes):